Production of alpha-naphthylamine



Fir o PEOID'UGTIOH O ALPHA-NAPHTHYL l lo To (ZZZ uni-om may concern;

Be it known .Jllfiu'ij it, STUART a citizen tile United States residing Philadelphia. county of i1 'la-deli ahia and State or Pennsylvania, have invented certain new and useful Improvements in the Production of Alpha-Napl'ztiiylainine of which the following is a specificetioni This invention relates to an improvement in the process of producing alpha-naphthyL amine. relates more particularly to the separation of the alpha-naphthylamine from. the iron oxide which is obtained es a byproduct from the customary process for the manufacture of alpha-naphthylamine,

In the Well-lmown and previously employed process for the manufacture of alphanaphthylamine the customary procedure has been as follows: Naphthalene was nitrated to mono-nitro-riaphthalene by treating" it with the required amount of nitric acid in the presence of the required amount of suiphuric acid, of the required concentration. The alpha-mono-nitro-naphthalene was sub stantiaily freed from the sulphuric ucid, and was then reduced to alphamaplithylamine by it with iron (preferably ror the purpose of distilling off the Y neplithylamine considerable in the form of iron boring. or shavings} and an acid (preferably hydrochloric acid). The alplramaphtiiylemine produced by this reduction Was mixed with a relatively large amount of iron oxide formed as a by-product in the reaction, and with a relatively small amount of unoxidized iron. The mixture of alpha-na-plithylamine, iron oxide and iron was then heated in a closed apparatus to di till off the alpha-naphthylamine. which condensed and again distilled in order to obtain a substantially pure product.

During the heating of the mixture of alphamaphthylarninae iron oxide iron alphadecomposition. of the alpha naphtliylaroine occurs due to the high temperature required, and a, considerable amount of valuable material is thereby lost. llfloreover, where a still is used the heavy iron oxide and iron tends to settle to the bottom of the still, forming a thiclr mess out material which conducts heat poorly, and tends to cause the still body to warp and crack. Also the operation of distilling the alpha-naphthylamine from the iron oxide is very unpleasant and dangerous.

application filed octobcr 2 P319 'mechanical operutior 'of this irrv on; 7 increase iii by dispene' w alplia-iiaplilliylamioe and iron, thereby l dent to this distiller;

Another object of eliminate the serious 0 the distillation from the iron oxide on l'n the process acre oi trcroeiy die-o "re ao'v 1 were generatdd d alphamaplrtiryiemim iron oxide and iron and iron handle tli by the ope able and eroue to the operation as l ln carr ing out lene is wit way to forroalpiir The alpha-memoir reduced alphamaplitiiy it with iron in presence eralx-ly hydrochloric eei produces iron oxide wit e al with the crud unoridized ir distiil the mixture with :1 the alpli:i--onpliil},' nopliiia ilfiS been purpose. A

naphtha is used to ."oal'e solution 1 ing' of about equal "pa alpha-napiltliylamine Willi c is maintained a The undissol unoxidized iron} 3 solution by a so talir )6, 1 il'm'iq' L rm gl 2) 'iiein l by centrifiigmg in a cenri by settling. .ln practicing this invention I prefer to separate the undissolved material by filtering through a tiller press.

"the lihrate, whi h consists ot' the alphanaphih vlaniinc in solution in the solvent. naphtha. is then distilled to remove tln naphtha. 'l'his nia he done in a steam he'. ed still leaving as a residue the crude alpha ncplnhylamine. This alpha-naphthylami1n ma}; he further refined ii) any of the well. l-umwn processes.

The iron oxide and iron reniaining in the tilter press is washed with solvent naphtha clear the same of alpha-naphthylamine,

"log; pumping naphtha through the tilter press. Solvent remaining in the press may afterwards he removed from the mixture of iron oxide and iron by steam distillation, vacuum drying, or in any other convenient way, so that the oxide and iron is thus rein dered substantially free (ll '11ll)ll:l-l]1l})lll.ll \'lamine. and solvent, but is lett sutlicientl moist to facilitate handlin; the same \vithoutv disagreeable dusting of the oxide.

The solvent recmelcd h v distilling the alpha-naphthylamine solution and that used in washing; the oxide may be used again in the process, as a solvent for alpha-naphthylamine.

It is my intention not to limit the scope of this application to the manut'acture of pure alpha-naphthylamine, but to include also the manufacture of thatproduct which is known in the arts as alpha-imphthylaminc and-which consists essentially of the chemical compound alpha-naphthylamine,-

STUART P. MILLER. 

